1 /* 2 * Battery charger driver for TI BQ24735 3 * 4 * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; 9 * 10 * This program is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along 16 * with this program; if not, write to the Free Software Foundation, Inc., 17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 */ 19 20 #include <linux/err.h> 21 #include <linux/gpio.h> 22 #include <linux/i2c.h> 23 #include <linux/init.h> 24 #include <linux/interrupt.h> 25 #include <linux/kernel.h> 26 #include <linux/module.h> 27 #include <linux/of.h> 28 #include <linux/gpio/consumer.h> 29 #include <linux/power_supply.h> 30 #include <linux/slab.h> 31 32 #include <linux/power/bq24735-charger.h> 33 34 #define BQ24735_CHG_OPT 0x12 35 #define BQ24735_CHG_OPT_CHARGE_DISABLE (1 << 0) 36 #define BQ24735_CHG_OPT_AC_PRESENT (1 << 4) 37 #define BQ24735_CHARGE_CURRENT 0x14 38 #define BQ24735_CHARGE_CURRENT_MASK 0x1fc0 39 #define BQ24735_CHARGE_VOLTAGE 0x15 40 #define BQ24735_CHARGE_VOLTAGE_MASK 0x7ff0 41 #define BQ24735_INPUT_CURRENT 0x3f 42 #define BQ24735_INPUT_CURRENT_MASK 0x1f80 43 #define BQ24735_MANUFACTURER_ID 0xfe 44 #define BQ24735_DEVICE_ID 0xff 45 46 struct bq24735 { 47 struct power_supply *charger; 48 struct power_supply_desc charger_desc; 49 struct i2c_client *client; 50 struct bq24735_platform *pdata; 51 struct mutex lock; 52 struct gpio_desc *status_gpio; 53 struct delayed_work poll; 54 u32 poll_interval; 55 bool charging; 56 }; 57 58 static inline struct bq24735 *to_bq24735(struct power_supply *psy) 59 { 60 return power_supply_get_drvdata(psy); 61 } 62 63 static enum power_supply_property bq24735_charger_properties[] = { 64 POWER_SUPPLY_PROP_STATUS, 65 POWER_SUPPLY_PROP_ONLINE, 66 }; 67 68 static int bq24735_charger_property_is_writeable(struct power_supply *psy, 69 enum power_supply_property psp) 70 { 71 switch (psp) { 72 case POWER_SUPPLY_PROP_STATUS: 73 return 1; 74 default: 75 break; 76 } 77 78 return 0; 79 } 80 81 static inline int bq24735_write_word(struct i2c_client *client, u8 reg, 82 u16 value) 83 { 84 return i2c_smbus_write_word_data(client, reg, value); 85 } 86 87 static inline int bq24735_read_word(struct i2c_client *client, u8 reg) 88 { 89 return i2c_smbus_read_word_data(client, reg); 90 } 91 92 static int bq24735_update_word(struct i2c_client *client, u8 reg, 93 u16 mask, u16 value) 94 { 95 unsigned int tmp; 96 int ret; 97 98 ret = bq24735_read_word(client, reg); 99 if (ret < 0) 100 return ret; 101 102 tmp = ret & ~mask; 103 tmp |= value & mask; 104 105 return bq24735_write_word(client, reg, tmp); 106 } 107 108 static int bq24735_config_charger(struct bq24735 *charger) 109 { 110 struct bq24735_platform *pdata = charger->pdata; 111 int ret; 112 u16 value; 113 114 if (pdata->ext_control) 115 return 0; 116 117 if (pdata->charge_current) { 118 value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK; 119 120 ret = bq24735_write_word(charger->client, 121 BQ24735_CHARGE_CURRENT, value); 122 if (ret < 0) { 123 dev_err(&charger->client->dev, 124 "Failed to write charger current : %d\n", 125 ret); 126 return ret; 127 } 128 } 129 130 if (pdata->charge_voltage) { 131 value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK; 132 133 ret = bq24735_write_word(charger->client, 134 BQ24735_CHARGE_VOLTAGE, value); 135 if (ret < 0) { 136 dev_err(&charger->client->dev, 137 "Failed to write charger voltage : %d\n", 138 ret); 139 return ret; 140 } 141 } 142 143 if (pdata->input_current) { 144 value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK; 145 146 ret = bq24735_write_word(charger->client, 147 BQ24735_INPUT_CURRENT, value); 148 if (ret < 0) { 149 dev_err(&charger->client->dev, 150 "Failed to write input current : %d\n", 151 ret); 152 return ret; 153 } 154 } 155 156 return 0; 157 } 158 159 static inline int bq24735_enable_charging(struct bq24735 *charger) 160 { 161 int ret; 162 163 if (charger->pdata->ext_control) 164 return 0; 165 166 ret = bq24735_config_charger(charger); 167 if (ret) 168 return ret; 169 170 return bq24735_update_word(charger->client, BQ24735_CHG_OPT, 171 BQ24735_CHG_OPT_CHARGE_DISABLE, 0); 172 } 173 174 static inline int bq24735_disable_charging(struct bq24735 *charger) 175 { 176 if (charger->pdata->ext_control) 177 return 0; 178 179 return bq24735_update_word(charger->client, BQ24735_CHG_OPT, 180 BQ24735_CHG_OPT_CHARGE_DISABLE, 181 BQ24735_CHG_OPT_CHARGE_DISABLE); 182 } 183 184 static bool bq24735_charger_is_present(struct bq24735 *charger) 185 { 186 if (charger->status_gpio) { 187 return !gpiod_get_value_cansleep(charger->status_gpio); 188 } else { 189 int ac = 0; 190 191 ac = bq24735_read_word(charger->client, BQ24735_CHG_OPT); 192 if (ac < 0) { 193 dev_dbg(&charger->client->dev, 194 "Failed to read charger options : %d\n", 195 ac); 196 return false; 197 } 198 return (ac & BQ24735_CHG_OPT_AC_PRESENT) ? true : false; 199 } 200 201 return false; 202 } 203 204 static int bq24735_charger_is_charging(struct bq24735 *charger) 205 { 206 int ret; 207 208 if (!bq24735_charger_is_present(charger)) 209 return 0; 210 211 ret = bq24735_read_word(charger->client, BQ24735_CHG_OPT); 212 if (ret < 0) 213 return ret; 214 215 return !(ret & BQ24735_CHG_OPT_CHARGE_DISABLE); 216 } 217 218 static void bq24735_update(struct bq24735 *charger) 219 { 220 mutex_lock(&charger->lock); 221 222 if (charger->charging && bq24735_charger_is_present(charger)) 223 bq24735_enable_charging(charger); 224 else 225 bq24735_disable_charging(charger); 226 227 mutex_unlock(&charger->lock); 228 229 power_supply_changed(charger->charger); 230 } 231 232 static irqreturn_t bq24735_charger_isr(int irq, void *devid) 233 { 234 struct power_supply *psy = devid; 235 struct bq24735 *charger = to_bq24735(psy); 236 237 bq24735_update(charger); 238 239 return IRQ_HANDLED; 240 } 241 242 static void bq24735_poll(struct work_struct *work) 243 { 244 struct bq24735 *charger = container_of(work, struct bq24735, poll.work); 245 246 bq24735_update(charger); 247 248 schedule_delayed_work(&charger->poll, 249 msecs_to_jiffies(charger->poll_interval)); 250 } 251 252 static int bq24735_charger_get_property(struct power_supply *psy, 253 enum power_supply_property psp, 254 union power_supply_propval *val) 255 { 256 struct bq24735 *charger = to_bq24735(psy); 257 258 switch (psp) { 259 case POWER_SUPPLY_PROP_ONLINE: 260 val->intval = bq24735_charger_is_present(charger) ? 1 : 0; 261 break; 262 case POWER_SUPPLY_PROP_STATUS: 263 switch (bq24735_charger_is_charging(charger)) { 264 case 1: 265 val->intval = POWER_SUPPLY_STATUS_CHARGING; 266 break; 267 case 0: 268 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; 269 break; 270 default: 271 val->intval = POWER_SUPPLY_STATUS_UNKNOWN; 272 break; 273 } 274 break; 275 default: 276 return -EINVAL; 277 } 278 279 return 0; 280 } 281 282 static int bq24735_charger_set_property(struct power_supply *psy, 283 enum power_supply_property psp, 284 const union power_supply_propval *val) 285 { 286 struct bq24735 *charger = to_bq24735(psy); 287 int ret; 288 289 switch (psp) { 290 case POWER_SUPPLY_PROP_STATUS: 291 switch (val->intval) { 292 case POWER_SUPPLY_STATUS_CHARGING: 293 mutex_lock(&charger->lock); 294 charger->charging = true; 295 ret = bq24735_enable_charging(charger); 296 mutex_unlock(&charger->lock); 297 if (ret) 298 return ret; 299 break; 300 case POWER_SUPPLY_STATUS_DISCHARGING: 301 case POWER_SUPPLY_STATUS_NOT_CHARGING: 302 mutex_lock(&charger->lock); 303 charger->charging = false; 304 ret = bq24735_disable_charging(charger); 305 mutex_unlock(&charger->lock); 306 if (ret) 307 return ret; 308 break; 309 default: 310 return -EINVAL; 311 } 312 power_supply_changed(psy); 313 break; 314 default: 315 return -EPERM; 316 } 317 318 return 0; 319 } 320 321 static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client) 322 { 323 struct bq24735_platform *pdata; 324 struct device_node *np = client->dev.of_node; 325 u32 val; 326 int ret; 327 328 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); 329 if (!pdata) { 330 dev_err(&client->dev, 331 "Memory alloc for bq24735 pdata failed\n"); 332 return NULL; 333 } 334 335 ret = of_property_read_u32(np, "ti,charge-current", &val); 336 if (!ret) 337 pdata->charge_current = val; 338 339 ret = of_property_read_u32(np, "ti,charge-voltage", &val); 340 if (!ret) 341 pdata->charge_voltage = val; 342 343 ret = of_property_read_u32(np, "ti,input-current", &val); 344 if (!ret) 345 pdata->input_current = val; 346 347 pdata->ext_control = of_property_read_bool(np, "ti,external-control"); 348 349 return pdata; 350 } 351 352 static int bq24735_charger_probe(struct i2c_client *client, 353 const struct i2c_device_id *id) 354 { 355 int ret; 356 struct bq24735 *charger; 357 struct power_supply_desc *supply_desc; 358 struct power_supply_config psy_cfg = {}; 359 char *name; 360 361 charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL); 362 if (!charger) 363 return -ENOMEM; 364 365 mutex_init(&charger->lock); 366 charger->charging = true; 367 charger->pdata = client->dev.platform_data; 368 369 if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node) 370 charger->pdata = bq24735_parse_dt_data(client); 371 372 if (!charger->pdata) { 373 dev_err(&client->dev, "no platform data provided\n"); 374 return -EINVAL; 375 } 376 377 name = (char *)charger->pdata->name; 378 if (!name) { 379 name = devm_kasprintf(&client->dev, GFP_KERNEL, 380 "bq24735@%s", 381 dev_name(&client->dev)); 382 if (!name) { 383 dev_err(&client->dev, "Failed to alloc device name\n"); 384 return -ENOMEM; 385 } 386 } 387 388 charger->client = client; 389 390 supply_desc = &charger->charger_desc; 391 392 supply_desc->name = name; 393 supply_desc->type = POWER_SUPPLY_TYPE_MAINS; 394 supply_desc->properties = bq24735_charger_properties; 395 supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties); 396 supply_desc->get_property = bq24735_charger_get_property; 397 supply_desc->set_property = bq24735_charger_set_property; 398 supply_desc->property_is_writeable = 399 bq24735_charger_property_is_writeable; 400 401 psy_cfg.supplied_to = charger->pdata->supplied_to; 402 psy_cfg.num_supplicants = charger->pdata->num_supplicants; 403 psy_cfg.of_node = client->dev.of_node; 404 psy_cfg.drv_data = charger; 405 406 i2c_set_clientdata(client, charger); 407 408 charger->status_gpio = devm_gpiod_get_optional(&client->dev, 409 "ti,ac-detect", 410 GPIOD_IN); 411 if (IS_ERR(charger->status_gpio)) { 412 ret = PTR_ERR(charger->status_gpio); 413 dev_err(&client->dev, "Getting gpio failed: %d\n", ret); 414 return ret; 415 } 416 417 if (bq24735_charger_is_present(charger)) { 418 ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID); 419 if (ret < 0) { 420 dev_err(&client->dev, "Failed to read manufacturer id : %d\n", 421 ret); 422 return ret; 423 } else if (ret != 0x0040) { 424 dev_err(&client->dev, 425 "manufacturer id mismatch. 0x0040 != 0x%04x\n", ret); 426 return -ENODEV; 427 } 428 429 ret = bq24735_read_word(client, BQ24735_DEVICE_ID); 430 if (ret < 0) { 431 dev_err(&client->dev, "Failed to read device id : %d\n", ret); 432 return ret; 433 } else if (ret != 0x000B) { 434 dev_err(&client->dev, 435 "device id mismatch. 0x000b != 0x%04x\n", ret); 436 return -ENODEV; 437 } 438 439 ret = bq24735_enable_charging(charger); 440 if (ret < 0) { 441 dev_err(&client->dev, "Failed to enable charging\n"); 442 return ret; 443 } 444 } 445 446 charger->charger = devm_power_supply_register(&client->dev, supply_desc, 447 &psy_cfg); 448 if (IS_ERR(charger->charger)) { 449 ret = PTR_ERR(charger->charger); 450 dev_err(&client->dev, "Failed to register power supply: %d\n", 451 ret); 452 return ret; 453 } 454 455 if (client->irq) { 456 ret = devm_request_threaded_irq(&client->dev, client->irq, 457 NULL, bq24735_charger_isr, 458 IRQF_TRIGGER_RISING | 459 IRQF_TRIGGER_FALLING | 460 IRQF_ONESHOT, 461 supply_desc->name, 462 charger->charger); 463 if (ret) { 464 dev_err(&client->dev, 465 "Unable to register IRQ %d err %d\n", 466 client->irq, ret); 467 return ret; 468 } 469 } else { 470 ret = device_property_read_u32(&client->dev, "poll-interval", 471 &charger->poll_interval); 472 if (ret) 473 return 0; 474 if (!charger->poll_interval) 475 return 0; 476 477 INIT_DELAYED_WORK(&charger->poll, bq24735_poll); 478 schedule_delayed_work(&charger->poll, 479 msecs_to_jiffies(charger->poll_interval)); 480 } 481 482 return 0; 483 } 484 485 static int bq24735_charger_remove(struct i2c_client *client) 486 { 487 struct bq24735 *charger = i2c_get_clientdata(client); 488 489 if (charger->poll_interval) 490 cancel_delayed_work_sync(&charger->poll); 491 492 return 0; 493 } 494 495 static const struct i2c_device_id bq24735_charger_id[] = { 496 { "bq24735-charger", 0 }, 497 {} 498 }; 499 MODULE_DEVICE_TABLE(i2c, bq24735_charger_id); 500 501 static const struct of_device_id bq24735_match_ids[] = { 502 { .compatible = "ti,bq24735", }, 503 { /* end */ } 504 }; 505 MODULE_DEVICE_TABLE(of, bq24735_match_ids); 506 507 static struct i2c_driver bq24735_charger_driver = { 508 .driver = { 509 .name = "bq24735-charger", 510 .of_match_table = bq24735_match_ids, 511 }, 512 .probe = bq24735_charger_probe, 513 .remove = bq24735_charger_remove, 514 .id_table = bq24735_charger_id, 515 }; 516 517 module_i2c_driver(bq24735_charger_driver); 518 519 MODULE_DESCRIPTION("bq24735 battery charging driver"); 520 MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>"); 521 MODULE_LICENSE("GPL v2"); 522